AbstractIntestinal cancer was induced in inbred male D/A rats by 1,2‐dimethylhydrazine, and the interrelationships between a high‐fat (33.5% w/w) diet, beer and alcohol (4.8% v/v) ingestion, and tumor location and incidence were examined. The number of tumors per animal was significantly greater in both the small and large intestines of rats on the high‐fat diet, as opposed to the standard died. The 6‐fold increase in incidence of colorectal cancer occurred almost exclusively in the distal half of the large bowel; i.e., there was a highly significant (p<0.005) shift, similar to that seen in man in countries adopting high‐fat Western‐type diets. Neither alcohol nor beer ingestion affected the incidence of intestinal cancers, but beer was associated with a more distal distribution of small‐intestinal cancers in animals on the high‐fat diet. However, this was not considered sufficient evidence for any material effect of beer on experimental intestinal carcinogenesis.(Nutr Cancer 6, 229–235, 1985)